Assessing perioperative risk Chronic Obstructive Pulmonary Disease Dr. Michelle Caldecott Respiratory & Sleep Physician Epworth Healthcare Austin Health
Impact of COPD on Postoperative Outcomes: Results From a National Database Gupta H., etal Chest. 2013;143(6):1599-1606 COPD No- COPD P- value Median length of stay 4 days 1 day P<0.0001 30 day morbidity 25.8% 10.2% P<0.0001 30 day mortality 6.7% 1.4% P<0.0001 Acute renal failure 1.52% 0.53% P<0.0001 AMI (within 6 mo) 2.68% 0.63% P<0.0001 After controlling for >50 comorbidities & type surgery, COPD was independently associated with: postoperative morbidity (OR, 1.35; 95% CI, 1.30-1.40; P <.0001) postoperative mortality (OR, 1.29; 95% CI, 1.19-1.39; P <.0001) 2
Assessing Risk of Postoperative Pulmonary Complications in COPD (and broadly). 1. Surgery related aspects 2. Anaesthesia related aspects 3. Patient related aspects 3
Surgery related aspects 1. Surgical site 2. Surgical time >3 hours 3. Emergency surgery 4
Anaesthesia related aspects Is Spinal or Epidural anaesthesia safer?? Conflicting data Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials Rodgers A, BMJ 2000;321:1493 Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not (with or without GA) 141 Trials, 9559 patients Outcome measures: All cause mortality, DVT, PE, AMI, pneumonia, respiratory depression, transfusions, ARF 5
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Intraoperative prophylactic and therapeutic non-invasive ventilation 7
Intraoperative prophylactic and therapeutic non-invasive ventilation COPD/ hyperinflation Intrinsic PEEP Premature airway collapse BiPAP = PS / PEEP load on respiratory mm Respiratory mm at mechanical disadvantage Respiratory pump failure PaCO2, acidosis 8
Intraoperative prophylactic and therapeutic non-invasive ventilation Cabrini etal, BJA Jan 2014 COPD/ hyperinflation Intrinsic PEEP load on respiratory mm Premature airway collapse PEEPe BiPAP Respiratory mm at mechanical disadvantage Respiratory pump failure = PS / PEEP PaCO2, acidosis 9
Intraoperative prophylactic and therapeutic non-invasive ventilation Cabrini etal, BJA Jan 2014 Reviewed 30 papers, small numbers Broadly, 2 types of applications: 1. Acute resp failure (CF, neuromuscular) 2. Prophylactic ( at risk, incl COPD) Only 3 failures reported Safe, feasible Especially for op in supine position Avoids intubation No RCT, case reports only 10
Patient Related Aspects - COPD Airflow obstruction comes in all shapes and sizes. 11
Airway wall remodelling (non smoking COPD) 12
Airway wall remodelling (non smoking COPD) Stiff pipes rather than holes in the sponge 13
COPD physiologically results in: Dynamic hyperinflation/ Gas trapping V/Q mismatching Diaphragm dysfunction Reduction in pulmonary capillary bed V/Q mismatching Alveolar hypoventilation Increased mucous production Pulmonary hypertension 14
COPD physiologically results in: Dynamic hyperinflation/ Gas trapping V/Q mismatching Diaphragm dysfunction Reduction in pulmonary capillary bed V/Q mismatching Alveolar hypoventilation Increased mucous production Pulmonary hypertension 15
Respiratory Function Tests (For non lung resection surgery) RFTs (Spirometry, CO diffusing capacity) alone do not predict postoperative risk Based on limited studies, there is no prohibitive level of pulmonary function RFTs indicated if: Obstructive lung disease requiring optimisation?reversibility Dyspnoea unexplained after clinical evaluation 16
Patient Related Aspects - COPD In COPD patients consider: - Current smoking - Presence of pulmonary hypertension -? Elevated PaCO2 -? Sputum production/volume - Overall health status (ASA classification) - Preoperative ex tolerance 17
Chest: CRITICAL CARE November 2011 Development and Validation of a Risk Calculator Predicting Postoperative Respiratory Failure Himani Gupta etal http://www.surgicalriskcalculator.com/p etrf-risk-calculator 18
Gupta Calculator Emergency case? ASA Class? Preoperative Function? Procedure? Sepsis? 19
Gupta etal 2011 20
Estimated risk probability for Postoperative Respiratory Failure (PRF) 10.68% Gupta etal 2011 21
Preop Anaesthetic Assessment: 22
Thankyou 23